| //===-- RuntimeDyld.cpp - Run-time dynamic linker for MC-JIT ----*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Implementation of the MC-JIT runtime dynamic linker. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #define DEBUG_TYPE "dyld" |
| #include "llvm/ExecutionEngine/RuntimeDyld.h" |
| #include "ObjectImageCommon.h" |
| #include "RuntimeDyldELF.h" |
| #include "RuntimeDyldImpl.h" |
| #include "RuntimeDyldMachO.h" |
| #include "llvm/Support/MathExtras.h" |
| #include "llvm/Support/Path.h" |
| |
| using namespace llvm; |
| using namespace llvm::object; |
| |
| // Empty out-of-line virtual destructor as the key function. |
| RTDyldMemoryManager::~RTDyldMemoryManager() {} |
| RuntimeDyldImpl::~RuntimeDyldImpl() {} |
| |
| namespace llvm { |
| |
| // Resolve the relocations for all symbols we currently know about. |
| void RuntimeDyldImpl::resolveRelocations() { |
| // First, resolve relocations associated with external symbols. |
| resolveExternalSymbols(); |
| |
| // Just iterate over the sections we have and resolve all the relocations |
| // in them. Gross overkill, but it gets the job done. |
| for (int i = 0, e = Sections.size(); i != e; ++i) { |
| uint64_t Addr = Sections[i].LoadAddress; |
| DEBUG(dbgs() << "Resolving relocations Section #" << i |
| << "\t" << format("%p", (uint8_t *)Addr) |
| << "\n"); |
| resolveRelocationList(Relocations[i], Addr); |
| } |
| } |
| |
| void RuntimeDyldImpl::mapSectionAddress(const void *LocalAddress, |
| uint64_t TargetAddress) { |
| for (unsigned i = 0, e = Sections.size(); i != e; ++i) { |
| if (Sections[i].Address == LocalAddress) { |
| reassignSectionAddress(i, TargetAddress); |
| return; |
| } |
| } |
| llvm_unreachable("Attempting to remap address of unknown section!"); |
| } |
| |
| // Subclasses can implement this method to create specialized image instances. |
| // The caller owns the pointer that is returned. |
| ObjectImage *RuntimeDyldImpl::createObjectImage(ObjectBuffer *InputBuffer) { |
| return new ObjectImageCommon(InputBuffer); |
| } |
| |
| ObjectImage *RuntimeDyldImpl::loadObject(ObjectBuffer *InputBuffer) { |
| OwningPtr<ObjectImage> obj(createObjectImage(InputBuffer)); |
| if (!obj) |
| report_fatal_error("Unable to create object image from memory buffer!"); |
| |
| Arch = (Triple::ArchType)obj->getArch(); |
| |
| // Symbols found in this object |
| StringMap<SymbolLoc> LocalSymbols; |
| // Used sections from the object file |
| ObjSectionToIDMap LocalSections; |
| |
| // Common symbols requiring allocation, with their sizes and alignments |
| CommonSymbolMap CommonSymbols; |
| // Maximum required total memory to allocate all common symbols |
| uint64_t CommonSize = 0; |
| |
| error_code err; |
| // Parse symbols |
| DEBUG(dbgs() << "Parse symbols:\n"); |
| for (symbol_iterator i = obj->begin_symbols(), e = obj->end_symbols(); |
| i != e; i.increment(err)) { |
| Check(err); |
| object::SymbolRef::Type SymType; |
| StringRef Name; |
| Check(i->getType(SymType)); |
| Check(i->getName(Name)); |
| |
| uint32_t flags; |
| Check(i->getFlags(flags)); |
| |
| bool isCommon = flags & SymbolRef::SF_Common; |
| if (isCommon) { |
| // Add the common symbols to a list. We'll allocate them all below. |
| uint32_t Align; |
| Check(i->getAlignment(Align)); |
| uint64_t Size = 0; |
| Check(i->getSize(Size)); |
| CommonSize += Size + Align; |
| CommonSymbols[*i] = CommonSymbolInfo(Size, Align); |
| } else { |
| if (SymType == object::SymbolRef::ST_Function || |
| SymType == object::SymbolRef::ST_Data || |
| SymType == object::SymbolRef::ST_Unknown) { |
| uint64_t FileOffset; |
| StringRef SectionData; |
| bool IsCode; |
| section_iterator si = obj->end_sections(); |
| Check(i->getFileOffset(FileOffset)); |
| Check(i->getSection(si)); |
| if (si == obj->end_sections()) continue; |
| Check(si->getContents(SectionData)); |
| Check(si->isText(IsCode)); |
| const uint8_t* SymPtr = (const uint8_t*)InputBuffer->getBufferStart() + |
| (uintptr_t)FileOffset; |
| uintptr_t SectOffset = (uintptr_t)(SymPtr - |
| (const uint8_t*)SectionData.begin()); |
| unsigned SectionID = findOrEmitSection(*obj, *si, IsCode, LocalSections); |
| LocalSymbols[Name.data()] = SymbolLoc(SectionID, SectOffset); |
| DEBUG(dbgs() << "\tFileOffset: " << format("%p", (uintptr_t)FileOffset) |
| << " flags: " << flags |
| << " SID: " << SectionID |
| << " Offset: " << format("%p", SectOffset)); |
| GlobalSymbolTable[Name] = SymbolLoc(SectionID, SectOffset); |
| } |
| } |
| DEBUG(dbgs() << "\tType: " << SymType << " Name: " << Name << "\n"); |
| } |
| |
| // Allocate common symbols |
| if (CommonSize != 0) |
| emitCommonSymbols(*obj, CommonSymbols, CommonSize, LocalSymbols); |
| |
| // Parse and process relocations |
| DEBUG(dbgs() << "Parse relocations:\n"); |
| for (section_iterator si = obj->begin_sections(), |
| se = obj->end_sections(); si != se; si.increment(err)) { |
| Check(err); |
| bool isFirstRelocation = true; |
| unsigned SectionID = 0; |
| StubMap Stubs; |
| |
| for (relocation_iterator i = si->begin_relocations(), |
| e = si->end_relocations(); i != e; i.increment(err)) { |
| Check(err); |
| |
| // If it's the first relocation in this section, find its SectionID |
| if (isFirstRelocation) { |
| SectionID = findOrEmitSection(*obj, *si, true, LocalSections); |
| DEBUG(dbgs() << "\tSectionID: " << SectionID << "\n"); |
| isFirstRelocation = false; |
| } |
| |
| processRelocationRef(SectionID, *i, *obj, LocalSections, LocalSymbols, |
| Stubs); |
| } |
| } |
| |
| return obj.take(); |
| } |
| |
| void RuntimeDyldImpl::emitCommonSymbols(ObjectImage &Obj, |
| const CommonSymbolMap &CommonSymbols, |
| uint64_t TotalSize, |
| SymbolTableMap &SymbolTable) { |
| // Allocate memory for the section |
| unsigned SectionID = Sections.size(); |
| uint8_t *Addr = MemMgr->allocateDataSection(TotalSize, sizeof(void*), |
| SectionID, false); |
| if (!Addr) |
| report_fatal_error("Unable to allocate memory for common symbols!"); |
| uint64_t Offset = 0; |
| Sections.push_back(SectionEntry(StringRef(), Addr, TotalSize, TotalSize, 0)); |
| memset(Addr, 0, TotalSize); |
| |
| DEBUG(dbgs() << "emitCommonSection SectionID: " << SectionID |
| << " new addr: " << format("%p", Addr) |
| << " DataSize: " << TotalSize |
| << "\n"); |
| |
| // Assign the address of each symbol |
| for (CommonSymbolMap::const_iterator it = CommonSymbols.begin(), |
| itEnd = CommonSymbols.end(); it != itEnd; it++) { |
| uint64_t Size = it->second.first; |
| uint64_t Align = it->second.second; |
| StringRef Name; |
| it->first.getName(Name); |
| if (Align) { |
| // This symbol has an alignment requirement. |
| uint64_t AlignOffset = OffsetToAlignment((uint64_t)Addr, Align); |
| Addr += AlignOffset; |
| Offset += AlignOffset; |
| DEBUG(dbgs() << "Allocating common symbol " << Name << " address " << |
| format("%p\n", Addr)); |
| } |
| Obj.updateSymbolAddress(it->first, (uint64_t)Addr); |
| SymbolTable[Name.data()] = SymbolLoc(SectionID, Offset); |
| Offset += Size; |
| Addr += Size; |
| } |
| } |
| |
| unsigned RuntimeDyldImpl::emitSection(ObjectImage &Obj, |
| const SectionRef &Section, |
| bool IsCode) { |
| |
| unsigned StubBufSize = 0, |
| StubSize = getMaxStubSize(); |
| error_code err; |
| if (StubSize > 0) { |
| for (relocation_iterator i = Section.begin_relocations(), |
| e = Section.end_relocations(); i != e; i.increment(err), Check(err)) |
| StubBufSize += StubSize; |
| } |
| StringRef data; |
| uint64_t Alignment64; |
| Check(Section.getContents(data)); |
| Check(Section.getAlignment(Alignment64)); |
| |
| unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL; |
| bool IsRequired; |
| bool IsVirtual; |
| bool IsZeroInit; |
| bool IsReadOnly; |
| uint64_t DataSize; |
| StringRef Name; |
| Check(Section.isRequiredForExecution(IsRequired)); |
| Check(Section.isVirtual(IsVirtual)); |
| Check(Section.isZeroInit(IsZeroInit)); |
| Check(Section.isReadOnlyData(IsReadOnly)); |
| Check(Section.getSize(DataSize)); |
| Check(Section.getName(Name)); |
| if (StubSize > 0) { |
| unsigned StubAlignment = getStubAlignment(); |
| unsigned EndAlignment = (DataSize | Alignment) & -(DataSize | Alignment); |
| if (StubAlignment > EndAlignment) |
| StubBufSize += StubAlignment - EndAlignment; |
| } |
| |
| unsigned Allocate; |
| unsigned SectionID = Sections.size(); |
| uint8_t *Addr; |
| const char *pData = 0; |
| |
| // Some sections, such as debug info, don't need to be loaded for execution. |
| // Leave those where they are. |
| if (IsRequired) { |
| Allocate = DataSize + StubBufSize; |
| Addr = IsCode |
| ? MemMgr->allocateCodeSection(Allocate, Alignment, SectionID) |
| : MemMgr->allocateDataSection(Allocate, Alignment, SectionID, IsReadOnly); |
| if (!Addr) |
| report_fatal_error("Unable to allocate section memory!"); |
| |
| // Virtual sections have no data in the object image, so leave pData = 0 |
| if (!IsVirtual) |
| pData = data.data(); |
| |
| // Zero-initialize or copy the data from the image |
| if (IsZeroInit || IsVirtual) |
| memset(Addr, 0, DataSize); |
| else |
| memcpy(Addr, pData, DataSize); |
| |
| DEBUG(dbgs() << "emitSection SectionID: " << SectionID |
| << " Name: " << Name |
| << " obj addr: " << format("%p", pData) |
| << " new addr: " << format("%p", Addr) |
| << " DataSize: " << DataSize |
| << " StubBufSize: " << StubBufSize |
| << " Allocate: " << Allocate |
| << "\n"); |
| Obj.updateSectionAddress(Section, (uint64_t)Addr); |
| } |
| else { |
| // Even if we didn't load the section, we need to record an entry for it |
| // to handle later processing (and by 'handle' I mean don't do anything |
| // with these sections). |
| Allocate = 0; |
| Addr = 0; |
| DEBUG(dbgs() << "emitSection SectionID: " << SectionID |
| << " Name: " << Name |
| << " obj addr: " << format("%p", data.data()) |
| << " new addr: 0" |
| << " DataSize: " << DataSize |
| << " StubBufSize: " << StubBufSize |
| << " Allocate: " << Allocate |
| << "\n"); |
| } |
| |
| Sections.push_back(SectionEntry(Name, Addr, Allocate, DataSize, |
| (uintptr_t)pData)); |
| return SectionID; |
| } |
| |
| unsigned RuntimeDyldImpl::findOrEmitSection(ObjectImage &Obj, |
| const SectionRef &Section, |
| bool IsCode, |
| ObjSectionToIDMap &LocalSections) { |
| |
| unsigned SectionID = 0; |
| ObjSectionToIDMap::iterator i = LocalSections.find(Section); |
| if (i != LocalSections.end()) |
| SectionID = i->second; |
| else { |
| SectionID = emitSection(Obj, Section, IsCode); |
| LocalSections[Section] = SectionID; |
| } |
| return SectionID; |
| } |
| |
| void RuntimeDyldImpl::addRelocationForSection(const RelocationEntry &RE, |
| unsigned SectionID) { |
| Relocations[SectionID].push_back(RE); |
| } |
| |
| void RuntimeDyldImpl::addRelocationForSymbol(const RelocationEntry &RE, |
| StringRef SymbolName) { |
| // Relocation by symbol. If the symbol is found in the global symbol table, |
| // create an appropriate section relocation. Otherwise, add it to |
| // ExternalSymbolRelocations. |
| SymbolTableMap::const_iterator Loc = |
| GlobalSymbolTable.find(SymbolName); |
| if (Loc == GlobalSymbolTable.end()) { |
| ExternalSymbolRelocations[SymbolName].push_back(RE); |
| } else { |
| // Copy the RE since we want to modify its addend. |
| RelocationEntry RECopy = RE; |
| RECopy.Addend += Loc->second.second; |
| Relocations[Loc->second.first].push_back(RECopy); |
| } |
| } |
| |
| uint8_t *RuntimeDyldImpl::createStubFunction(uint8_t *Addr) { |
| if (Arch == Triple::arm) { |
| // TODO: There is only ARM far stub now. We should add the Thumb stub, |
| // and stubs for branches Thumb - ARM and ARM - Thumb. |
| uint32_t *StubAddr = (uint32_t*)Addr; |
| *StubAddr = 0xe51ff004; // ldr pc,<label> |
| return (uint8_t*)++StubAddr; |
| } else if (Arch == Triple::mipsel || Arch == Triple::mips) { |
| uint32_t *StubAddr = (uint32_t*)Addr; |
| // 0: 3c190000 lui t9,%hi(addr). |
| // 4: 27390000 addiu t9,t9,%lo(addr). |
| // 8: 03200008 jr t9. |
| // c: 00000000 nop. |
| const unsigned LuiT9Instr = 0x3c190000, AdduiT9Instr = 0x27390000; |
| const unsigned JrT9Instr = 0x03200008, NopInstr = 0x0; |
| |
| *StubAddr = LuiT9Instr; |
| StubAddr++; |
| *StubAddr = AdduiT9Instr; |
| StubAddr++; |
| *StubAddr = JrT9Instr; |
| StubAddr++; |
| *StubAddr = NopInstr; |
| return Addr; |
| } else if (Arch == Triple::ppc64) { |
| // PowerPC64 stub: the address points to a function descriptor |
| // instead of the function itself. Load the function address |
| // on r11 and sets it to control register. Also loads the function |
| // TOC in r2 and environment pointer to r11. |
| writeInt32BE(Addr, 0x3D800000); // lis r12, highest(addr) |
| writeInt32BE(Addr+4, 0x618C0000); // ori r12, higher(addr) |
| writeInt32BE(Addr+8, 0x798C07C6); // sldi r12, r12, 32 |
| writeInt32BE(Addr+12, 0x658C0000); // oris r12, r12, h(addr) |
| writeInt32BE(Addr+16, 0x618C0000); // ori r12, r12, l(addr) |
| writeInt32BE(Addr+20, 0xF8410028); // std r2, 40(r1) |
| writeInt32BE(Addr+24, 0xE96C0000); // ld r11, 0(r12) |
| writeInt32BE(Addr+28, 0xE84C0008); // ld r2, 0(r12) |
| writeInt32BE(Addr+32, 0x7D6903A6); // mtctr r11 |
| writeInt32BE(Addr+36, 0xE96C0010); // ld r11, 16(r2) |
| writeInt32BE(Addr+40, 0x4E800420); // bctr |
| |
| return Addr; |
| } else if (Arch == Triple::systemz) { |
| writeInt16BE(Addr, 0xC418); // lgrl %r1,.+8 |
| writeInt16BE(Addr+2, 0x0000); |
| writeInt16BE(Addr+4, 0x0004); |
| writeInt16BE(Addr+6, 0x07F1); // brc 15,%r1 |
| // 8-byte address stored at Addr + 8 |
| return Addr; |
| } |
| return Addr; |
| } |
| |
| // Assign an address to a symbol name and resolve all the relocations |
| // associated with it. |
| void RuntimeDyldImpl::reassignSectionAddress(unsigned SectionID, |
| uint64_t Addr) { |
| // The address to use for relocation resolution is not |
| // the address of the local section buffer. We must be doing |
| // a remote execution environment of some sort. Relocations can't |
| // be applied until all the sections have been moved. The client must |
| // trigger this with a call to MCJIT::finalize() or |
| // RuntimeDyld::resolveRelocations(). |
| // |
| // Addr is a uint64_t because we can't assume the pointer width |
| // of the target is the same as that of the host. Just use a generic |
| // "big enough" type. |
| Sections[SectionID].LoadAddress = Addr; |
| } |
| |
| void RuntimeDyldImpl::resolveRelocationList(const RelocationList &Relocs, |
| uint64_t Value) { |
| for (unsigned i = 0, e = Relocs.size(); i != e; ++i) { |
| const RelocationEntry &RE = Relocs[i]; |
| // Ignore relocations for sections that were not loaded |
| if (Sections[RE.SectionID].Address == 0) |
| continue; |
| resolveRelocation(RE, Value); |
| } |
| } |
| |
| void RuntimeDyldImpl::resolveExternalSymbols() { |
| StringMap<RelocationList>::iterator i = ExternalSymbolRelocations.begin(), |
| e = ExternalSymbolRelocations.end(); |
| for (; i != e; i++) { |
| StringRef Name = i->first(); |
| RelocationList &Relocs = i->second; |
| SymbolTableMap::const_iterator Loc = GlobalSymbolTable.find(Name); |
| if (Loc == GlobalSymbolTable.end()) { |
| if (Name.size() == 0) { |
| // This is an absolute symbol, use an address of zero. |
| DEBUG(dbgs() << "Resolving absolute relocations." << "\n"); |
| resolveRelocationList(Relocs, 0); |
| } else { |
| // This is an external symbol, try to get its address from |
| // MemoryManager. |
| uint8_t *Addr = (uint8_t*) MemMgr->getPointerToNamedFunction(Name.data(), |
| true); |
| DEBUG(dbgs() << "Resolving relocations Name: " << Name |
| << "\t" << format("%p", Addr) |
| << "\n"); |
| resolveRelocationList(Relocs, (uintptr_t)Addr); |
| } |
| } else { |
| report_fatal_error("Expected external symbol"); |
| } |
| } |
| } |
| |
| |
| //===----------------------------------------------------------------------===// |
| // RuntimeDyld class implementation |
| RuntimeDyld::RuntimeDyld(RTDyldMemoryManager *mm) { |
| // FIXME: There's a potential issue lurking here if a single instance of |
| // RuntimeDyld is used to load multiple objects. The current implementation |
| // associates a single memory manager with a RuntimeDyld instance. Even |
| // though the public class spawns a new 'impl' instance for each load, |
| // they share a single memory manager. This can become a problem when page |
| // permissions are applied. |
| Dyld = 0; |
| MM = mm; |
| } |
| |
| RuntimeDyld::~RuntimeDyld() { |
| delete Dyld; |
| } |
| |
| ObjectImage *RuntimeDyld::loadObject(ObjectBuffer *InputBuffer) { |
| if (!Dyld) { |
| sys::LLVMFileType type = sys::IdentifyFileType( |
| InputBuffer->getBufferStart(), |
| static_cast<unsigned>(InputBuffer->getBufferSize())); |
| switch (type) { |
| case sys::ELF_Relocatable_FileType: |
| case sys::ELF_Executable_FileType: |
| case sys::ELF_SharedObject_FileType: |
| case sys::ELF_Core_FileType: |
| Dyld = new RuntimeDyldELF(MM); |
| break; |
| case sys::Mach_O_Object_FileType: |
| case sys::Mach_O_Executable_FileType: |
| case sys::Mach_O_FixedVirtualMemorySharedLib_FileType: |
| case sys::Mach_O_Core_FileType: |
| case sys::Mach_O_PreloadExecutable_FileType: |
| case sys::Mach_O_DynamicallyLinkedSharedLib_FileType: |
| case sys::Mach_O_DynamicLinker_FileType: |
| case sys::Mach_O_Bundle_FileType: |
| case sys::Mach_O_DynamicallyLinkedSharedLibStub_FileType: |
| case sys::Mach_O_DSYMCompanion_FileType: |
| Dyld = new RuntimeDyldMachO(MM); |
| break; |
| case sys::Unknown_FileType: |
| case sys::Bitcode_FileType: |
| case sys::Archive_FileType: |
| case sys::COFF_FileType: |
| report_fatal_error("Incompatible object format!"); |
| } |
| } else { |
| if (!Dyld->isCompatibleFormat(InputBuffer)) |
| report_fatal_error("Incompatible object format!"); |
| } |
| |
| return Dyld->loadObject(InputBuffer); |
| } |
| |
| void *RuntimeDyld::getSymbolAddress(StringRef Name) { |
| return Dyld->getSymbolAddress(Name); |
| } |
| |
| uint64_t RuntimeDyld::getSymbolLoadAddress(StringRef Name) { |
| return Dyld->getSymbolLoadAddress(Name); |
| } |
| |
| void RuntimeDyld::resolveRelocations() { |
| Dyld->resolveRelocations(); |
| } |
| |
| void RuntimeDyld::reassignSectionAddress(unsigned SectionID, |
| uint64_t Addr) { |
| Dyld->reassignSectionAddress(SectionID, Addr); |
| } |
| |
| void RuntimeDyld::mapSectionAddress(const void *LocalAddress, |
| uint64_t TargetAddress) { |
| Dyld->mapSectionAddress(LocalAddress, TargetAddress); |
| } |
| |
| StringRef RuntimeDyld::getErrorString() { |
| return Dyld->getErrorString(); |
| } |
| |
| } // end namespace llvm |